The present invention relates to toothbrushes, and more particularly, to toothbrushes having a particular bristle pattern which by penetrating into the interproximal spaces between the teeth and which by providing an improved sweeping effect, in combination enhanced the cleaning of the tooth surfaces.
The primary purpose of a toothbrush is to clean the teeth by removing plaque and debris from the tooth surfaces, including the curved outer tooth surfaces and the interproximal surfaces between the teeth, i.e. the topography of the teeth. To facilitate such cleaning, conventional toothbrushes comprise generally uniform length tufts of bristles, a flat bristle trim, each bristle having a first end which is held captive in and fixed to a brush head, and a second, free end, which is used for brushing. Toothbrushes having such a generally flat bristle trim are limited in their ability to conform to the curvature of the teeth, to penetrate into the interproximal areas between the teeth and to sweep away the plaque and debris as bristles within a flat bristle trim tend to interfere with each other.
The desire of users to cause brushes having such conventional flat bristle trims to conform to the curvature of the teeth and to penetrate into the interproximal spaces between the teeth expressed by the forceful application of the brush to adequately deform the bristles to the tooth topography. Such forceful application of the brush causes excessive, deleterious wear of the tooth surfaces and gums, without providing adequate conformation of the brush about and between the teeth to yield the desired cleaning.
U.S. Pat. No. 5,742,972 discloses a toothbrush having a bristle trim containing at the toe region of the head, furthest from the handle, a ramping down subset of bristle tufts with the longest bristle tuft adjacent to the toe. Along the heel region of the head, closest to the handle, is a plurality of bristle rows trimmed along the longitudinal axis of the head in the form of a trough. This combination of bristle trim is designed to provide enhanced interproximal and gingival margin cleaning by better conforming to the curved surfaces of and between the teeth. While this combination of tufts does provide better conformity to the topography of the teeth than a conventional uniform length, flat trim toothbrush; it does not have the spacing and diversity of tufts and trim necessary to provide the desired conformity to and between the teeth for enhanced cleaning of the tooth surfaces.
Alternately, U.S. Pat. Nos. 5,335,389, 5,341,537, 5,446,940 and 5,459,899 disclose various other toothbrushes containing combinations of longer and shorter bristle tufts and bristle bars, which are generally orthogonal to the face of the disclosed toothbrushes, but do include acutely angled bristle groupings, either as discrete bristle tufts and/or continuous bristle bars. As in the case of U.S. Pat. No. 5,742,972, the bristle patterns of these toothbrushes will better conform to and between the curved surfaces of the teeth than a conventional flat trim pattern; but, as in the case of U.S. Pat. No. 5,742,972, the spacing and diversity of bristle groupings does not provide the enhanced conformity to and between the teeth for the desired cleaning.
U.S. Design Pat. Nos. 422,143 and 425,306 disclose bristle patterns characterized by a generally flat bristle trim and three spaced apart, bristle bars disposed transverse to the longitudinal axis of the toothbrush head and spaced away from the ends of the brush head. As conventional toothbrush heads are generally about 3 cm in length, such three bristle bars dispositions, spaced away from the ends of the brush head, would allow only about 2 centimeters of longitudinal brush head length for the three bristle bars, i.e. the bristle bars being at most 1 cm apart. Considering the trend toward larger adult molars of 1 cm or more across, the at most spacing of 1 cm between the bristle bars disclosed within the subject design patents will not facilitate the bristle bars penetration into the interproximal spaces between such molars. Further, the presence of three bristle bars, with such a spacing, that extend transversely across the brush head will tend to cause at least one of the bristle bars to abut against the surface of one of the smaller anterior teeth such as the incisors, so as prevent the other bristle bars from penetrating into and cleaning the interproximal spaces between such teeth. Without easy penetration by the bristle bars into the interproximal spaces the user will tend to apply excessive brushing pressure to force the bristle bars to penetrate about the sides of the molars and between the incisors, cuspids, bicuspids and molars, causing the deleterious wear discussed above.
There is a need in the art for a toothbrush having a bristle pattern with the ability to easily penetrate into the interproximal spaces, to better conform to the curvature of the teeth, and to provide a better sweeping effect, in combination to provide improved dentiture cleaning, without the need for the application of excessive and deleterious brushing force.
The present invention comprises a toothbrush with an elongated head connected to an elongated handle, which head is divided into three sections by two rows of bristle tufts or bristle bars oriented transversely across the head, extending in height at least about 1.0 cm above the face of the toothbrush and spaced at least 1.2 cm apart; wherein, the first section, located nearest the toe of the brush, contains at least two rows of bristle tufts oriented transversely across the brush head, wherein the trim profile of the bristle tufts which comprise these rows is curved, having a first radius of curvature convex with respect to the toe of the toothbrush; and wherein the second section, located between the two transverse rows of bristle tufts, contains a plurality of rows of bristle tufts with a curved trim profile, having a second radius of curvature convex to the face of the toothbrush; and wherein, the third section, located nearest the handle of the toothbrush, contains at least two transverse rows of bristle tufts with a curved trim profile, having a third radius of curvature convex with respect to the handle end of the toothbrush head; which combination of features provides a configuration of bristle tufts able to conform to the curvature of the tooth, while more easily penetrating the interproximal spaces between the teeth, and providing a better sweeping effect to remove plaque and debris from both the surface of and between the teeth.
A second embodiment of the present invention comprises the three sections of bristle tufts of the first embodiment described above; except, rather than the bristle trim profiles of the three sections of bristle tufts being curved, the trim profile of each section is a flat plane or combination of flat planes. Specifically, the profile trim of the free ends of the first and third sections each lie in a flat plane angled downward toward the center of the face of the toothbrush head from the respective ends of the head. The profile trim of the free ends of the second, center section, is an inverted xe2x80x9cVxe2x80x9d, formed of two flat planes with an apex at its center, each plane respectively descending toward the toe and handle ends of the head. This profile bristle trim allows further separation between the bristles ends to facilitate an enhanced sweeping effect, to provide enhanced cleaning of the tooth surfaces.
A third embodiment of the present invention comprises the three sections of bristle tufts of the first embodiment, wherein the bristle tufts in the second section are comprised of an inner grouping of bristle tufts, located central to the toothbrush face, which inner grouping is acutely angled toward either the toe or handle end of the toothbrush head and an outer grouping of bristle tufts located about the periphery of the face, which outer grouping is acutely angled toward the opposite end of the head than the inner grouping. The rows of bristle tufts within both the inner and outer groupings may be arranged in columns which are generally aligned with and parallel to the longitudinal axis of the brush head. This third embodiment further enhances the ability of the toothbrush to penetrate into the interproximal spaces as the toothbrush is moved horizontally back and forth in the mouth.